Liquid cooling plate vacuum brazing device and method thereof

Abstract

The application discloses a kind of liquid cooling plate vacuum brazing device and method thereof, belong to vacuum brazing technical field, including speed chain assembly, two groups of workbench and vacuum brazing furnace (not shown in figure), first tray is installed on the speed chain assembly, two groups of the workbench between installation is used to load the composite feeding mechanism for the liquid cooling cover plate and nickel-based composite welding piece, the right side of the speed chain assembly is installed for the liquid cooling cover plate and nickel-based composite welding piece and is used to compact limit welding mechanism.The composite feeding mechanism cooperates with the micro vacuum chuck and the pressing frame in the above manner, realizes the automatic feeding and positioning of the nickel-based composite welding piece and the liquid cooling cover plate, the chuck is blocked by vertical pick-and-place cooperation with the pressing frame, to avoid the deformation of the sheet welding piece, ensure that the sheet is placed flat;Opening pressing box is synchronously compacted on both sides of the liquid cooling cover plate, so that the cover plate remains horizontal during the laser continuous welding process without tilting, to avoid the cover plate from tilting due to one-sided compacting, affecting the sealing performance.

Description

Technical Field

[0001] This invention relates to the field of vacuum brazing technology, and more specifically to a vacuum brazing apparatus and method for liquid-cooled plates. Background Technology

[0002] As the core carrier of heat exchange, the sealing reliability, welded joint performance, and structural dimensional accuracy of liquid cooling plates directly determine the safety and service life of equipment operation.

[0003] Chinese patent CN122033372A discloses a clamping structure for vacuum brazing and a vacuum brazing method for aluminum alloy plates. The clamping structure provided for vacuum brazing provides equipment conditions for optimizing the welding effect of the vacuum welding method on aluminum alloy weldments, thereby improving the welding rate and weld strength of the welded surfaces during the vacuum brazing process. However, each vacuum brazing process takes 10-12 hours, and the introduction of fixtures in vacuum brazing will significantly reduce production efficiency.

[0004] Chinese patent CN108356376A discloses a surface treatment method to improve the performance of brazed joints. By plating nickel on the surface of a nickel-based alloy, the mechanical properties of the weld are significantly improved. This is because the nickel layer dissolves elements such as boron and silicon, and the nickel in the nickel layer diffuses into the base material and the isothermal solidification zone, increasing the solubility of other elements in the diffusion zone and reducing the formation of brittle phases in the diffusion zone. However, since the liquid cooling plate assembly in this invention requires a certain degree of corrosion resistance, overall nickel plating will lead to a decrease in its corrosion resistance.

[0005] In summary, for the existing liquid-cooled plate forming process, the introduction of brazing fixtures in vacuum brazing will significantly reduce production efficiency. Although the commonly used nickel-based brazing sheet vacuum brazing with nickel plating on the base material can effectively reduce the generation of brittle phases, the overall nickel plating will lead to a decrease in its corrosion resistance.

[0006] Meanwhile, when the nickel-based composite welding sheet is arranged between the liquid cooling module cover plate and the liquid cooling module body using the vacuum brazing method of the present invention, the existing assembly structure is prone to deformation of the nickel-based composite welding sheet due to its thinness, which in turn reduces the sealing performance of the liquid cooling module. In addition, when performing continuous laser welding on the liquid cooling module cover plate and the liquid cooling module body, if the welding side and the corresponding non-welding side of the liquid cooling module cover plate are not pressed simultaneously, the liquid cooling module cover plate may tilt, resulting in a decrease in the sealing performance of the liquid cooling module.

[0007] Based on this, the present invention designs a vacuum brazing device and method for liquid-cooled plates to solve the above problems. Summary of the Invention

[0008] In view of the above-mentioned shortcomings of the prior art, the present invention provides a vacuum brazing device and method for liquid-cooled plates.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A vacuum brazing device for liquid-cooled plates includes a double-speed chain assembly, two sets of worktables and a vacuum brazing furnace (not shown in the figure). A first material tray is installed on the double-speed chain assembly, a second material tray is fixedly connected to the upper surface of one set of worktables, and a third material tray is fixedly connected to the upper surface of the other set of worktables.

[0011] A composite feeding mechanism for feeding liquid-cooled cover plates and nickel-based composite welding sheets is installed between the two sets of workbenches;

[0012] The right side of the double-speed chain assembly is equipped with a clamping and limiting welding mechanism for pressing and limiting the liquid-cooled cover plate and the nickel-based composite welding sheet.

[0013] The workbench is equipped with four sets of auxiliary limiting components for auxiliary positioning of the first material tray; the limiting welding mechanism includes a support frame, a horizontal moving component, a welding component and a pressing component. The support frame is connected to two sets of horizontal moving components, one set of horizontal moving components is connected to the welding component, and the other set of horizontal moving components is connected to the pressing component. The pressing component is used to press and limit the liquid-cooled cover plate and the nickel-based composite weld sheet, and the welding component is used to weld the joint between the liquid-cooled cover plate and the nickel-based composite weld sheet.

[0014] Furthermore, the speed-doubled chain assembly includes a speed-doubled chain, a blocking cylinder, and a lifting mechanism. The speed-doubled chain is fixedly connected to the blocking cylinder and the lifting mechanism. The blocking cylinder is used to block the first material tray, and the lifting mechanism is used to lift and limit the first material tray.

[0015] Furthermore, the horizontal moving component includes a first linear module and a second linear module. The first linear module is fixedly connected to the outer surface of the double-speed chain component. The output end of the first linear module is fixedly connected to the second linear module. The output ends of one set of second linear modules are connected to the welding component, and the output ends of another set of second linear modules are connected to the pressing component.

[0016] Furthermore, the welding assembly includes a fixed frame and a laser welding head. The fixed frame is fixedly connected to the output end of the second linear module of a set of horizontally moving components, and the fixed frame is fixedly connected to the laser welding head.

[0017] Furthermore, the pressing assembly includes a second sliding frame, a second cylinder, a sliding plate, and an open pressing box. The second sliding frame is fixedly connected to the output end of the second linear module of another set of horizontal moving components. The upper surface of the second sliding frame is fixedly connected to two sets of second cylinders. The second sliding frame is slidably connected to the sliding plate. The output ends of the two sets of second cylinders are fixedly connected to the sliding plate. The lower surface of the sliding plate is fixedly connected to the open pressing box.

[0018] Furthermore, the opening contour of the pressure box is aligned with the inner cavity contour of the liquid cooling cover plate to avoid compressing the gaps inside the liquid cooling cover plate, which could cause deformation of the liquid cooling cover plate.

[0019] Furthermore, the composite feeding mechanism includes a robotic arm and a suction cup feeding assembly, with the output end of the robotic arm connected to the suction cup feeding assembly.

[0020] Furthermore, the suction cup feeding assembly includes a first sliding frame, a first cylinder, a fixed plate, a miniature vacuum suction cup, a sliding frame, and a pressing frame. The first sliding frame is fixedly connected to the output end of the robotic arm, the first sliding frame is fixedly connected to the first cylinder, the outer surface of the first sliding frame is fixedly connected to the fixed plate, the interior of the fixed plate is fixedly connected to multiple sets of miniature vacuum suction cups, the output end of the first cylinder is fixedly connected to the sliding frame, the sliding frame is slidably connected to the first sliding frame, and the outer surface of the sliding frame is fixedly connected to the pressing frame.

[0021] Furthermore, the auxiliary limiting component includes a lever cylinder and a pressure plate. The outer surface of the lever cylinder is fixedly connected to the speed-doubler chain, and the output end of the lever cylinder is fixedly connected to the pressure plate. The pressure plate is used to press and limit the first material tray.

[0022] To better achieve the objectives of this invention, this invention also provides a vacuum brazing method for liquid-cooled plates, comprising the following steps:

[0023] Step 1: Place a nickel-based composite welding sheet at the location where the liquid-cooled cover plate and the liquid-cooled plate body will be brazed. The nickel-based composite welding sheet is in contact with the pure Ni metal layer on both sides, and the middle layer is a nickel-based welding sheet. The thickness of the pure Ni layer is 0.01-0.03mm, and the thickness of the nickel-based welding sheet layer is 0.05mm.

[0024] Step 2: After pressing the liquid-cooled cover plate and the liquid-cooled plate body together with the first material tray and the open pressure box, the laser welding head performs continuous laser welding. The gap between the liquid-cooled cover plate and the liquid-cooled plate body is 5-20μm.

[0025] Step 3: Then, the liquid-cooled cover plate, the liquid-cooled plate body, and the nickel-based composite welding sheet after continuous laser welding are placed in batches in a vacuum brazing furnace for vacuum brazing.

[0026] Compared with the prior art, the beneficial effects of this invention are as follows: 1. A liquid cooling plate body is placed inside the first material tray. Then, a blocking cylinder blocks the movement of the first material tray following the double-speed chain, and a lifting mechanism limits and lifts the first material tray. At the same time, an auxiliary limiting component limits the side of the first material tray, thereby fixing the first material tray. This prevents the movement of the first material tray from affecting the installation accuracy when nickel-based composite welding sheets and liquid cooling cover plates are sequentially installed inside the liquid cooling plate body on the first material tray. Then, a composite feeding mechanism sequentially installs the nickel-based composite welding sheets and liquid cooling cover plates inside the liquid cooling plate body. The composite feeding mechanism also prevents deformation of the nickel-based composite welding sheets during installation. To address the issue of reduced sealing performance of the liquid cooling plate, another set of horizontal moving components controls the movement of the pressing component to press the liquid cooling plate body, which has been fitted with nickel-based composite welding sheets and liquid cooling cover plates, on both sides. Simultaneously, a set of horizontal moving components controls the movement of the welding component to perform continuous laser welding at the joint between the pressed liquid cooling cover plate and the nickel-based composite welding sheets. This avoids the problem that if the welding side of the liquid cooling cover plate and the nickel-based composite welding sheets and their corresponding non-welded sides are not pressed simultaneously, the liquid cooling component cover plate may tilt, leading to a decrease in the sealing performance of the liquid cooling plate. Then, the liquid cooling cover plate, liquid cooling plate body and nickel-based composite welding sheets that have undergone continuous laser welding are placed in batches into the interior of a vacuum brazing furnace for vacuum brazing.

[0027] 2. The composite feeding mechanism, in conjunction with a micro vacuum chuck and a pressure frame, enables automatic feeding and positioning of nickel-based composite welding sheets and liquid-cooled cover plates. The vertical placement of the chuck, combined with the blocking effect of the pressure frame, prevents deformation of the thin welding sheets and ensures that the welding sheets are placed flat. The open pressure box simultaneously presses the liquid-cooled cover plate on both sides, keeping the cover plate horizontal and preventing it from tilting during continuous laser welding. This avoids tilting of the cover plate due to unilateral pressing, which could affect the sealing performance. At the same time, the use of nickel-based composite welding sheets eliminates the need for brazing fixtures, significantly improving production efficiency. Furthermore, the pure nickel layers on both sides of the composite welding sheet effectively reduce the precipitation of brittle phases, ensuring the mechanical properties and corrosion resistance of the weld. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0029] Figure 1 This is a 3D view of the liquid cooling plate assembly;

[0030] Figure 2 This is a schematic diagram of the structure of a nickel-based composite solder sheet;

[0031] Figure 3A perspective view of a vacuum brazing device for liquid-cooled plates;

[0032] Figure 4 A top view of a vacuum brazing apparatus for liquid-cooled plates;

[0033] Figure 5 for Figure 3 Enlarged view of the structure at point A in the middle;

[0034] Figure 6 for Figure 3 Enlarged view of the structure at point B;

[0035] Figure 7 A cross-sectional view of a vacuum brazing device for liquid-cooled plates;

[0036] Figure 8 for Figure 7 Enlarged view of the structure at point C;

[0037] Figure 9 This is a schematic diagram of the suction cup feeding assembly.

[0038] The labels in the diagram represent:

[0039] 1. Double-speed chain assembly; 11. Double-speed chain; 12. Blocking cylinder; 13. Lifting mechanism; 2. First material tray; 3. Worktable; 4. Second material tray; 5. Third material tray; 6. Composite feeding mechanism; 61. Robotic arm; 62. Suction cup feeding assembly; 621. First sliding frame; 622. First cylinder; 623. Fixed plate; 624. Miniature vacuum suction cup; 625. Sliding frame; 626. Pressing frame; 7. Limiting welding mechanism; 71. Support frame; 72. Horizontal moving assembly; 721, First linear module; 722, Second linear module; 73, Welding assembly; 731, Fixing frame; 732, Laser welding head; 74, Pressing assembly; 741, Second sliding frame; 742, Second cylinder; 743, Sliding plate; 744, Open pressing box; 8, Auxiliary limiting assembly; 81, Lever cylinder; 82, Pressing plate; 9, Liquid cooling plate assembly; 91, Liquid cooling cover plate; 92, Liquid cooling plate body; 93, Nickel-based composite welding sheet. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] Example 1: In some embodiments, please refer to the accompanying drawings. Figures 1-9 A vacuum brazing device for liquid-cooled plates includes a double-speed chain assembly 1, two sets of worktables 3 and a vacuum brazing furnace (not shown in the figure). A first material tray 2 is installed on the double-speed chain assembly 1, a second material tray 4 is fixedly connected to the upper surface of one set of worktables 3, and a third material tray 5 is fixedly connected to the upper surface of the other set of worktables 3.

[0042] A composite feeding mechanism 6 is installed between the two sets of workbenches 3 for feeding the liquid-cooled cover plate 91 and the nickel-based composite welding sheet 93.

[0043] The right side of the double-speed chain assembly 1 is equipped with a clamping and limiting welding mechanism 7 for pressing and limiting the liquid-cooled cover plate 91 and the nickel-based composite welding sheet 93;

[0044] The workbench 3 is equipped with four sets of auxiliary limiting components 8 for auxiliary limiting of the first material tray 2; the limiting welding mechanism 7 includes a support frame 71, a horizontal moving component 72, a welding component 73 and a pressing component 74. The support frame 71 is connected to two sets of horizontal moving components 72, one set of horizontal moving components 72 is connected to the welding component 73, and the other set of horizontal moving components 72 is connected to the pressing component 74. The pressing component 74 is used to press and limit the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93. The welding component 73 is used to weld the joint between the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93.

[0045] The double-speed chain assembly 1 includes a double-speed chain 11, a blocking cylinder 12, and a lifting mechanism 13. The double-speed chain 11 is fixedly connected to the blocking cylinder 12 and the lifting mechanism 13. The blocking cylinder 12 is used to block the first material tray 2, and the lifting mechanism 13 is used to lift and limit the first material tray 2.

[0046] In this embodiment, a liquid cooling plate body 92 is placed inside the first material tray 2. Then, the first material tray 2, which moves with the speed-multiplying chain 11, is blocked by the blocking cylinder 12. The first material tray 2 is limited and lifted by the lifting mechanism 13. At the same time, the auxiliary limiting component 8 limits the side of the first material tray 2, thereby fixing the first material tray 2. This prevents the movement of the first material tray 2 from affecting the installation accuracy when the nickel-based composite welding sheet 93 and the liquid cooling cover plate 91 are installed sequentially inside the liquid cooling plate body 92 on the first material tray 2. Then, the composite feeding mechanism 6 installs the nickel-based composite welding sheet 93 and the liquid cooling cover plate 91 sequentially inside the liquid cooling plate body 92. The composite feeding mechanism 6 also prevents the nickel-based composite welding sheet 93 from deforming during installation, which would affect the subsequent brazing quality of the liquid cooling cover plate 91 and the liquid cooling plate body 92 and reduce the sealing performance of the liquid cooling plate.

[0047] Then another set of horizontal moving components 72 controls the movement of the pressing component 74 to press the liquid cooling plate body 92, which has the nickel-based composite welding sheet 93 and the liquid cooling cover plate 91 installed in sequence, on both sides. At the same time, a set of horizontal moving components 72 controls the movement of the welding component 73 to perform continuous laser welding on the joint between the pressed liquid cooling cover plate 91 and the nickel-based composite welding sheet 93. This avoids the problem that if the welding side of the liquid cooling cover plate 91 and the nickel-based composite welding sheet 93 and its corresponding non-welding side are not pressed simultaneously, the liquid cooling component cover plate may tilt, resulting in a decrease in the sealing performance of the liquid cooling plate.

[0048] Then, the liquid-cooled cover plate 91, the liquid-cooled plate body 92, and the nickel-based composite welding sheet 93, which have undergone continuous laser welding, are placed in batches into the interior of a vacuum brazing furnace for vacuum brazing.

[0049] Example 2: In some embodiments, such as Figures 1-9 As shown, in a preferred embodiment of the present invention, the horizontal moving component 72 includes a first linear module 721 and a second linear module 722. The first linear module 721 is fixedly connected to the outer surface of the double-speed chain component 1. The output end of the first linear module 721 is fixedly connected to the second linear module 722. The output ends of one set of second linear modules 722 are connected to the welding component 73, and the output ends of another set of second linear modules 722 are connected to the pressing component 74.

[0050] The welding assembly 73 includes a fixing frame 731 and a laser welding head 732. The fixing frame 731 is fixedly connected to the output end of a set of second linear modules 722 of the horizontal moving assembly 72, and the fixing frame 731 is fixedly connected to the laser welding head 732.

[0051] The pressing assembly 74 includes a second sliding frame 741, a second cylinder 742, a sliding plate 743, and an open pressing box 744. The second sliding frame 741 is fixedly connected to the output end of the second linear module 722 of another set of horizontal moving assemblies 72. The upper surface of the second sliding frame 741 is fixedly connected to two sets of second cylinders 742. The second sliding frame 741 is slidably connected to the sliding plate 743. The output ends of the two sets of second cylinders 742 are fixedly connected to the sliding plate 743. The lower surface of the sliding plate 743 is fixedly connected to the open pressing box 744.

[0052] The inner side of the open pressure box 744 is flush with the inner side of the liquid cooling cover plate 91 to avoid compressing the gaps inside the liquid cooling cover plate 91, which would cause the nickel-based composite welding sheet 93 to deform.

[0053] There is a distance between the side of the open pressure box 744 and the mating point of the liquid cooling cover plate 91 and the nickel-based composite welding sheet 93, so as to avoid the open pressure box 744 affecting the welding of the mating point of the liquid cooling cover plate 91 and the nickel-based composite welding sheet 93.

[0054] A vision sensor is fixedly connected to the lower surface of the fixed bracket 731, and a vision sensor is fixedly connected to the lower surface of the sliding plate 743.

[0055] The composite feeding mechanism 6 includes a robotic arm 61 and a suction cup feeding assembly 62, with the output end of the robotic arm 61 connected to the suction cup feeding assembly 62.

[0056] The suction cup feeding assembly 62 includes a first sliding frame 621, a first cylinder 622, a fixed plate 623, a miniature vacuum suction cup 624, a sliding frame 625, and a pressing frame 626. The first sliding frame 621 is fixedly connected to the output end of the robotic arm 61. The first sliding frame 621 is fixedly connected to the first cylinder 622. The outer surface of the first sliding frame 621 is fixedly connected to the fixed plate 623. The interior of the fixed plate 623 is fixedly connected to multiple sets of miniature vacuum suction cups 624. The output end of the first cylinder 622 is fixedly connected to the sliding frame 625. The sliding frame 625 is slidably connected to the first sliding frame 621. The outer surface of the sliding frame 625 is fixedly connected to the pressing frame 626.

[0057] Multiple sets of miniature vacuum suction cups 624 are connected to a fixed plate 623. The fixed plate 623 is connected to a vacuum generator through a pipe and is used to perform negative pressure suction on the multiple sets of miniature vacuum suction cups 624.

[0058] The auxiliary limiting component 8 includes a lever cylinder 81 and a pressure plate 82. The outer surface of the lever cylinder 81 is fixedly connected to the speed-doubler chain 11, and the output end of the lever cylinder 81 is fixedly connected to the pressure plate 82. The pressure plate 82 is used to press and limit the first material tray 2.

[0059] In this embodiment, a liquid cooling plate body 92 is placed inside the first material tray 2. Then, the first material tray 2, which moves with the speed-doubler chain 11, is blocked by the blocking cylinder 12. The first material tray 2 is limited and lifted by the lifting mechanism 13. At the same time, four sets of lever cylinders 81 push the pressure plate 82 to limit the side of the first material tray 2, thereby fixing the first material tray 2. This prevents the movement of the first material tray 2 from affecting the installation accuracy when the nickel-based composite welding sheet 93 and the liquid cooling cover plate 91 are installed sequentially inside the liquid cooling plate body 92 on the first material tray 2.

[0060] Then, the robotic arm 61 moves the miniature vacuum chuck 624 via the first sliding frame 621 and the fixed plate 623, causing the miniature vacuum chuck 624 to grip the nickel-based composite weld sheet 93 located inside the third material tray 5. The robotic arm 61 moves the nickel-based composite weld sheet 93 above the liquid cooling plate body 92 on the first material tray 2 and keeps it vertical. At this time, the robotic arm 61 moves the miniature vacuum chuck 624 vertically downward via the first sliding frame 621, so that the miniature vacuum chuck 624 is installed inside the liquid cooling plate body 92. Then, the robotic arm 61 moves vertically upward, and when the miniature vacuum chuck 624 exits the liquid cooling plate body 92, the first cylinder 622 pushes the sliding frame 625 downward, and the sliding frame 625 pushes the pressing frame 626 downward. The process involves blocking the nickel-based composite weld sheet 93 located inside the liquid cooling plate body 92, preventing the nickel-based composite weld sheet 93 from being moved out of the liquid cooling plate body 92 along with the micro vacuum chuck 624. Then, through the above steps, a liquid cooling cover plate 91 is placed inside the liquid cooling plate body 92 after the nickel-based composite weld sheet 93 is installed. The liquid cooling cover plate 91 is pushed downward by the pressure frame 626, preventing the liquid cooling cover plate 91 from being moved out of the liquid cooling plate body 92 along with the micro vacuum chuck 624. The nickel-based composite weld sheet 93 is picked up by multiple sets of micro vacuum chucks 624, avoiding deformation of the nickel-based composite weld sheet 93 during installation, which would affect the subsequent brazing quality of the liquid cooling cover plate 91 and the liquid cooling plate body 92 and cause a reduction in the sealing performance of the liquid cooling plate.

[0061] Then, another set of first linear modules 721 and second linear modules 722 drive the pressing assembly 74 to move, and observe the liquid-cooled cover plate 91 and nickel-based composite welded sheet 93 through vision sensor 2. When the open pressing box 744 moves to directly above the liquid-cooled cover plate 91 and nickel-based composite welded sheet 93, vision sensor 2 controls the first linear module 721 and second linear module 722 to stop moving through PLC. At the same time, the second cylinder 742 pulls the sliding plate 743 to move downward. The sliding plate 743 drives the open pressing box 744 to move downward, so that the open pressing box 744 presses down to press the liquid-cooled cover plate 91, the liquid-cooled plate body 92 and the nickel-based composite welded sheet 93, and presses the liquid-cooled plate body 92, which has the nickel-based composite welded sheet 93 and the liquid-cooled cover plate 91 installed in sequence, to press on both sides.

[0062] Simultaneously, a first linear module 721 and a second linear module 722 drive the welding assembly 73 to move, and observe the mating point between the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93 through a vision sensor. When the laser welding head 732 moves directly above the mating point between the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93, the vision sensor controls the first linear module 721 and the second linear module 722 via a PLC to move horizontally along the mating point between the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93, and performs continuous laser welding through the laser welding head 732. This avoids the problem that if the welding side of the liquid-cooled cover plate 91 and the nickel-based composite weld sheet 93 and its corresponding non-welding side are not pressed simultaneously, the liquid-cooled assembly cover plate may tilt, leading to a decrease in the sealing performance of the liquid-cooled plate.

[0063] Then, the liquid-cooled cover plate 91, the liquid-cooled plate body 92, and the nickel-based composite welding sheet 93, which have undergone continuous laser welding, are placed in batches into the interior of a vacuum brazing furnace for vacuum brazing.

[0064] Example 3: In some embodiments, as a preferred embodiment of the present invention, a vacuum brazing method for liquid-cooled plates includes the following steps:

[0065] Step 1: Place a nickel-based composite welding sheet 93 at the position where the liquid cooling cover plate 91 and the liquid cooling plate body 92 are brazed. The nickel-based composite welding sheet 93 is in contact with the pure Ni metal layer on both sides, and the middle layer is a nickel-based welding sheet. The thickness of the pure Ni layer is 0.01-0.03mm, and the thickness of the nickel-based welding sheet layer is 0.05mm.

[0066] Step 2: After pressing the liquid-cooled cover plate 91 and the liquid-cooled plate body 92 together with the first material tray 2 and the open pressure box 744, the laser welding head 732 performs continuous laser welding. The gap between the liquid-cooled cover plate 91 and the liquid-cooled plate body 92 is 5-20μm.

[0067] Step 3: Then, the liquid-cooled cover plate 91, the liquid-cooled plate body 92, and the nickel-based composite welding sheet 93, which have been continuously laser-welded, are placed in batches in a vacuum brazing furnace for vacuum brazing.

[0068] The nickel-based composite welding sheet 93 is a nickel-based welding sheet containing Cr and one of the elements B or Si, such as BNi-1, BNi-2, BNi-3, BNi-4, BNi-5, BNi-9, BNi-10, BNi-11, and BNi-14.

[0069] When the nickel-based composite brazing sheet 93 is placed inside the liquid-cooled cover plate 91, the width of the brazing sheet should exceed 1 / 3 of the actual brazing width so that the brazing sheet can fully fill the brazing gap when the brazing melts.

[0070] After continuous laser welding, the penetration depth should be 80% of the thickness of the weld plate. The penetration depth should not be too deep to prevent deformation of the liquid cooling plate due to excessive power during continuous laser welding, and the remaining unpenetrated areas can be effectively filled with solder.

[0071] Comparative Example 1: Refer to Example 3, except that the penetration depth of the laser continuous welding in step 2 is 100% of the plate thickness.

[0072] Comparative Example 2: Refer to Example 3, except that the penetration depth of the laser continuous welding in step two is 60% of the plate thickness.

[0073] Comparative Example 3: Refer to Example 3, except that in step one, the width of the solder pad is equal to the brazing width.

[0074] Comparative Example 4: Referring to Example 3, the difference is that in step one, the width of the solder pad exceeds 2 / 3 of the actual brazing width.

[0075] Comparative Example 5: Referring to Example 3, the difference is that the solder sheet in step one is a conventional nickel-based solder sheet.

[0076] Weld observation and brittle phase analysis were performed on the longitudinal joints after welding in Example 3 and Comparative Examples 1-5, respectively.

[0077] The test results are shown in Table 1 below.

[0078] Table 1. Observation results of welds in Example 3 and Comparative Examples 1-5

[0079] Examples / Comparative Examples Solder filler ratio % Brittle phase ratio % Example 3 100 3.2 Comparative Example 1 56 2.6 Comparative Example 2 89 3.5 Comparative Example 3 92 3.8 Comparative Example 4 100 2.5 Comparative Example 5 100 13.5

[0080] As shown in Table 1, Example 3 and Comparative Examples 1-5, excessively high penetration depth in laser continuous welding can lead to cover plate deformation, changes in the brazing gap, and a decrease in the solder filling ratio. Conversely, insufficient penetration depth results in incomplete filling of the brazing gap due to insufficient solder. Furthermore, when the weld pad width is parallel to the weld pad placement groove, the volume decreases due to solid-liquid conversion, preventing the solder from completely filling the brazing gap. Even when the weld pad width is too wide, although the solder can fully fill the brazing gap, some overflows into the liquid cooling plate cavity. This overflow can trigger a stronger galvanic cell reaction when the coolant passes through during AI server operation, leading to a decrease in the corrosion resistance of the liquid cooling plate cavity. Additionally, the introduction of composite weld pads can effectively reduce the precipitation of brittle phases.

[0081] Compared with related technologies, the vacuum brazing-laser welding composite connection technology for liquid-cooled plate assemblies provided by this invention has the following advantages:

[0082] 1. The AI ​​server liquid cooling plate assembly 9 produced by this invention has good airtightness and no leakage was found under helium leak detection.

[0083] 2. In view of the large size of the AI ​​server liquid cooling plate assembly 9 of the present invention, the use of brazing fixtures when using welding pads will greatly reduce production efficiency. After the welding pads are placed, the mating position is welded by continuous laser welding. After entering the furnace, there is no need to use brazing fixtures for fixation. In addition, the width of the welding pads is longer than the width of the welding pads, so that the solder can fully fill the brazing gap during brazing.

[0084] 3. When vacuum brazing stainless steel with nickel-based composite welding sheet 93, Cr in the base material diffuses into the weld and forms a brittle phase with B or Si. The nickel-based composite welding sheet 93 was redesigned to use a composite laminate structure with a nickel-based welding sheet in the middle and Ni metal layers on both sides. When brazing begins, the Ni metal layers act as an ion diffusion barrier, preventing Cr in the base material from diffusing into the weld and reducing the tendency of Cr to form a brittle phase with B or Si.

[0085] In summary, this invention addresses the molding requirements of the AI ​​server liquid cooling plate assembly 9 by employing a composite welding sheet + laser continuous welding molding process, which not only significantly improves production efficiency but also ensures zero leakage in the AI ​​server through the use of dual welding processes.

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vacuum brazing apparatus for liquid-cooled plates, comprising a double-speed chain assembly (1), two sets of worktables (3), and a vacuum brazing furnace (not shown in the figure), wherein a first material tray (2) is mounted on the double-speed chain assembly (1), a second material tray (4) is fixedly connected to the upper surface of one set of worktables (3), and a third material tray (5) is fixedly connected to the upper surface of the other set of worktables (3), characterized in that: A composite feeding mechanism (6) for feeding liquid-cooled cover plate (91) and nickel-based composite welding sheet (93) is installed between the two sets of workbenches (3). The right side of the double-speed chain assembly (1) is equipped with a clamping and limiting welding mechanism (7) for pressing and limiting the liquid-cooled cover plate (91) and the nickel-based composite welding sheet (93). The workbench (3) is equipped with four sets of auxiliary limiting components (8) for auxiliary limiting of the first material tray (2); the limiting welding mechanism (7) includes a support frame (71), a horizontal moving component (72), a welding component (73) and a pressing component (74). The support frame (71) is connected to two sets of horizontal moving components (72), one set of horizontal moving components (72) is connected to the welding component (73), and the other set of horizontal moving components (72) is connected to the pressing component (74). The pressing component (74) is used to press and limit the liquid-cooled cover plate (91) and the nickel-based composite weld sheet (93). The welding component (73) is used to weld the joint between the liquid-cooled cover plate (91) and the nickel-based composite weld sheet (93).

2. The vacuum brazing apparatus for liquid-cooled plates according to claim 1, characterized in that, The speed-double chain assembly (1) includes a speed-double chain (11), a blocking cylinder (12) and a lifting mechanism (13). The speed-double chain (11) is fixedly connected to the blocking cylinder (12) and the lifting mechanism (13). The blocking cylinder (12) is used to block the first material tray (2), and the lifting mechanism (13) is used to lift and limit the first material tray (2).

3. The vacuum brazing apparatus for liquid-cooled plates according to claim 2, characterized in that, The horizontal moving component (72) includes a first linear module (721) and a second linear module (722). The first linear module (721) is fixedly connected to the outer surface of the double speed chain component (1). The output end of the first linear module (721) is fixedly connected to the second linear module (722). The output end of one set of second linear modules (722) is connected to the welding component (73), and the output end of another set of second linear modules (722) is connected to the pressing component (74).

4. The vacuum brazing apparatus for liquid-cooled plates according to claim 3, characterized in that, The welding assembly (73) includes a fixing frame (731) and a laser welding head (732). The fixing frame (731) is fixedly connected to the output end of the second linear module (722) of a set of horizontal moving components (72), and the fixing frame (731) is fixedly connected to the laser welding head (732).

5. The vacuum brazing apparatus for liquid-cooled plates according to claim 4, characterized in that, The pressing assembly (74) includes a second sliding frame (741), a second cylinder (742), a sliding plate (743), and an open pressing box (744). The second sliding frame (741) is fixedly connected to the output end of the second linear module (722) of another set of horizontal moving assemblies (72). The upper surface of the second sliding frame (741) is fixedly connected to two sets of second cylinders (742). The second sliding frame (741) is slidably connected to the sliding plate (743). The output ends of the two sets of second cylinders (742) are fixedly connected to the sliding plate (743). The lower surface of the sliding plate (743) is fixedly connected to the open pressing box (744).

6. The vacuum brazing apparatus for liquid-cooled plates according to claim 5, characterized in that, The opening contour of the open pressure box (744) is aligned with the inner cavity contour of the liquid cooling cover plate (91) to avoid pressing the gap inside the liquid cooling cover plate (91) and causing deformation of the liquid cooling cover plate (91).

7. The vacuum brazing apparatus for liquid-cooled plates according to claim 6, characterized in that, The composite feeding mechanism (6) includes a robotic arm (61) and a suction cup feeding assembly (62), with the output end of the robotic arm (61) connected to the suction cup feeding assembly (62).

8. The vacuum brazing apparatus for liquid-cooled plates according to claim 7, characterized in that, The suction cup feeding assembly (62) includes a first sliding frame (621), a first cylinder (622), a fixed plate (623), a miniature vacuum suction cup (624), a sliding frame (625), and a pressing frame (626). The first sliding frame (621) is fixedly connected to the output end of the robotic arm (61), the first sliding frame (621) is fixedly connected to the first cylinder (622), the outer surface of the first sliding frame (621) is fixedly connected to the fixed plate (623), the interior of the fixed plate (623) is fixedly connected to multiple sets of miniature vacuum suction cups (624), the output end of the first cylinder (622) is fixedly connected to the sliding frame (625), the sliding frame (625) is slidably connected to the first sliding frame (621), and the outer surface of the sliding frame (625) is fixedly connected to the pressing frame (626).

9. The vacuum brazing apparatus for liquid-cooled plates according to claim 8, characterized in that, The auxiliary limiting component (8) includes a lever cylinder (81) and a pressure plate (82). The outer surface of the lever cylinder (81) is fixedly connected to the double speed chain (11), and the output end of the lever cylinder (81) is fixedly connected to the pressure plate (82). The pressure plate (82) is used to press and limit the first material tray (2).

10. A method for vacuum brazing a liquid-cooled plate, utilizing any one of the vacuum brazing apparatuses described in 1-9, characterized in that, Includes the following steps: Step 1: Place a nickel-based composite welding sheet (93) at the position where the liquid cooling cover plate (91) and the liquid cooling plate body (92) are brazed. The nickel-based composite welding sheet (93) is in contact with the pure Ni metal layer on both sides, and the middle layer is a nickel-based welding sheet. The thickness of the pure Ni layer is 0.01-0.03mm, and the thickness of the nickel-based welding sheet layer is 0.05mm. Step 2: After pressing the liquid-cooled cover plate (91) and the liquid-cooled plate body (92) together with the first material tray (2) and the open pressure box (744), the laser welding head (732) performs continuous laser welding on it. The gap between the liquid-cooled cover plate (91) and the liquid-cooled plate body (92) is 5-20μm. Step 3: Then, the liquid-cooled cover plate (91), the liquid-cooled plate body (92), and the nickel-based composite welding sheet (93) after continuous laser welding are placed in a vacuum brazing furnace for vacuum brazing.

Images